Editing Velociraptor (section)

==Paleobiology==
===Feathers===
In 2007 Alan H. Turner and colleagues reported the presence of six [[quill knobs]] in the ulna of a referred ''Velociraptor'' specimen (IGM 100/981) from the Ukhaa Tolgod locality of the [[Djadochta Formation]]. Turner and colleagues interpreted the presence of feathers on ''Velociraptor'' as evidence against the idea that the larger, flightless [[maniraptora]]ns lost their feathers secondarily due to larger body size. Furthermore, they noted that quill knobs are almost never found in flightless bird species today, and that their presence in ''Velociraptor'' (presumed to have been flightless due to its relatively large size and short forelimbs) is evidence that the ancestors of dromaeosaurids could fly, making ''Velociraptor'' and other large members of this family secondarily flightless, though it is possible the large wing feathers inferred in the ancestors of ''Velociraptor'' had a purpose other than flight. The feathers of the flightless ''Velociraptor'' may have been used for display, for covering their nests while brooding, or for added speed and thrust when running up inclined slopes.<ref name=Turneer2007/>

Because of the presence of another dromaeosaurid in Ukhaa Tolgod, ''[[Tsaagan]]'', Napoli and team have noted that the referral of this specimen to ''Velociraptor'' is currently subject to reexamination.<ref name=Napoli2021/>

===Senses===
Examinations of the endocranium of ''Velociraptor'' indicate that it was able to detect and hear a wide range of sound frequencies (2,368–3,965&nbsp;Hz) and could track prey with ease as a result. The endocranium examinations also further cemented the theory that the dromaeosaur was an agile, swift predator. Fossil evidence suggesting ''Velociraptor'' scavenged also indicates that it was an opportunistic and actively predatory animal, feeding on carrion during times of drought or famine, if in poor health, or depending on the animal's age.<ref>{{Cite journal|doi=10.1111/joa.13253|title=The endocranium and trophic ecology of Velociraptor mongoliensis|year=2020|last1=King|first1=J. Logan|last2=Sipla|first2=Justin S.|last3=Georgi|first3=Justin A.|last4=Balanoff|first4=Amy M.|last5=Neenan|first5=James M.|journal=Journal of Anatomy|volume=237|issue=5|pages=861–869|pmid=32648601|pmc=7542195|doi-access=free}}</ref>

===Feeding===
In 2020, Powers and colleagues re-examined the [[maxillae]] of several [[Eudromaeosauria|eudromaeosaur]] taxa concluding that most Asian and North American eudromaeosaurs were separated by snout morphology and ecological strategies. They found the maxilla to be a reliable reference when inferring the shape of the [[premaxilla]] and overall [[snout]]. For instance, most Asian species have elongated snouts based on the maxilla (namely [[velociraptorines]]), indicating a selective feeding in ''Velociraptor'' and relatives, such as picking up small, fast prey. In contrast, most North American eudromaeosaurs, mostly dromaeosaurines, feature a robust and deep maxillar morphology. However, the large dromaeosurine ''Achillobator'' is a unique exception to Asian taxa with its deep maxilla.<ref name=Powers2020>{{cite journal|last1=Powers|first1=M. A.|last2=Sullivan|first2=C.|last3=Currie|first3=P. J.|date=2020|title=Re-examining ratio based premaxillary and maxillary characters in Eudromaeosauria (Dinosauria: Theropoda): Divergent trends in snout morphology between Asian and North American taxa|journal=Palaeogeography, Palaeoclimatology, Palaeoecology|volume=547|number=109704|page=109704 |bibcode=2020PPP...54709704P|doi=10.1016/j.palaeo.2020.109704|s2cid=216499705}}</ref>

Manabu Sakamoto in 2022 performed a Bayesian phylogenetic predictive modelling framework for estimating jaw muscle parameters and bite forces of several extinct archosaurs, based on skull widths and phylogenetic relationships between groups. Among studied taxa, ''Velociraptor'' was scored with a bite force of 304 [[Newton (unit)|N]], which was lower than that of other dromaeosaurids such as ''[[Dromaeosaurus]]'' (885 N) or ''[[Deinonychus]]'' (706 N).<ref>{{cite journal|last1=Sakamoto|first1=M.|date=2022|title=Estimating bite force in extinct dinosaurs using phylogenetically predicted physiological cross-sectional areas of jaw adductor muscles|journal=PeerJ|volume=10|pages=e13731|doi=10.7717/peerj.13731|doi-access=free|pmc=9285543|pmid=35846881}}</ref>

===Predatory behavior===
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|image1 = Fighting dinosaurs (1).jpg
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|image2 = Velociraptor v. Protoceratops (fixed).jpg
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|footer = The "Fighting Dinosaurs" specimen of ''V. mongoliensis'' and ''Protoceratops andrewsi'' and restoration of same
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The "[[Fighting Dinosaurs]]" specimen, found in 1971, preserves a ''Velociraptor mongoliensis'' and ''[[Protoceratops|Protoceratops andrewsi]]'' in combat and provides direct evidence of predatory behavior. When originally reported, it was hypothesized that the two animals drowned.<ref name=barsbold1974/> However, as the animals were preserved in ancient sand dune deposits, it is now thought that the animals were buried in sand, either from a collapsing dune or in a [[Dust storm|sandstorm]]. Burial must have been extremely rapid, judging from the lifelike poses in which the animals were preserved. Parts of the ''Protoceratops'' are missing, which has been seen as evidence of [[scavenger|scavenging]] by other animals.<ref name=carpenter1998>{{cite journal|last=Carpenter |first=Kenneth |author-link=Kenneth Carpenter |year=1998 |title=Evidence of predatory behavior by theropod dinosaurs |journal=Gaia |volume=15 |pages=135–144 |url=http://www.mnhn.ul.pt/geologia/gaia/9.pdf |url-status=dead |archive-url=https://web.archive.org/web/20110719060017/http://www.mnhn.ul.pt/geologia/gaia/9.pdf |archive-date=19 July 2011 }}</ref> Comparisons between the [[sclerotic ring|scleral rings]] of ''Velociraptor'', ''Protoceratops'', and modern birds and reptiles indicates that ''Velociraptor'' may have been [[nocturnal]], while ''Protoceratops'' may have been [[cathemeral]], active throughout the day during short intervals, suggesting that the fight may have occurred at twilight or during low-light conditions.<ref>{{cite journal|author1=Schmitz, L. |author2=Motani, R. |year=2011 |title=Nocturnality in Dinosaurs Inferred from Scleral Ring and Orbit Morphology |journal=Science |volume=332 |issue=6030|pages=705–8|doi=10.1126/science.1200043 |pmid=21493820|bibcode=2011Sci...332..705S|s2cid=33253407 }}</ref>
[[File:Fighting Dinosaurs size.png|thumb|Size comparison of the Fighting Dinosaurs]]
The distinctive claw, on the second digit of dromaeosaurids, has traditionally been depicted as a slashing weapon; its assumed use being to cut and [[disembowel]] prey.<ref name=ostrom1969>{{cite book |last=Ostrom |first=John H. |author-link=John Ostrom |year=1969 |title=Osteology of ''Deinonychus antirrhopus'', an unusual theropod from the Lower Cretaceous of Montana |publisher=Bulletin of the Peabody Museum of Natural History |volume=30 |pages=1–165|doi=10.2307/j.ctvqc6gzx|s2cid=210733704 }}</ref> In the "Fighting Dinosaurs" specimen, the ''Velociraptor'' lies underneath, with one of its sickle claws apparently embedded in the throat of its prey, while the beak of ''Protoceratops'' is clamped down upon the right forelimb of its attacker. This suggests ''Velociraptor'' may have used its sickle claw to pierce vital organs of the throat, such as the [[jugular vein]], [[carotid artery]], or [[vertebrate trachea|trachea]] (windpipe), rather than slashing the abdomen. The inside edge of the claw was rounded and not unusually sharp, which may have precluded any sort of cutting or slashing action, although only the bony core of the claw is preserved. The thick abdominal wall of [[skin]] and [[muscle]] of large prey species would have been difficult to slash without a specialized cutting surface.<ref name=carpenter1998/> The slashing [[hypothesis]] was tested during a 2005 [[BBC]] documentary, ''[[The Truth About Killer Dinosaurs]]''. The producers of the program created an artificial ''Velociraptor'' leg with a sickle claw and used a [[pork belly]] to simulate the dinosaur's prey. Though the sickle claw did penetrate the abdominal wall, it was unable to tear it open, indicating that the claw was not used to disembowel prey.<ref>{{cite journal |last1=Manning |first1=P. L. |last2=Payne |first2=D. |last3=Pennicott |first3=J. |last4=Barrett |first4=P. M. |last5=Ennos |first5=R. A. |year=2006 |title=Dinosaur killer claws or climbing crampons? |journal=Biology Letters |volume=2 |issue=1|pages=110–112 |doi=10.1098/rsbl.2005.0395 |pmid=17148340 |pmc=1617199}}</ref>

Remains of ''[[Deinonychus]]'', a closely related dromaeosaurid, have commonly been found in aggregations of several individuals. ''Deinonychus'' has also been found in association with the large ornithopod ''[[Tenontosaurus]]'', which has been cited as evidence of cooperative (pack) hunting.<ref name=maxwellostrom1995>{{cite journal|doi=10.1080/02724634.1995.10011256 |last1=Maxwell |first1=W. Desmond |author-link2=John Ostrom |last2=Ostrom |first2=John H. |year=1995 |title=Taphonomy and paleobiological implications of Tenontosaurus-Deinonychus associations |journal=Journal of Vertebrate Paleontology |volume=15 |issue=4 |pages=707–712 |bibcode=1995JVPal..15..707M |url=http://vertpaleo.org/publications/jvp/15-707-712.cfm |url-status=dead |archive-url=https://web.archive.org/web/20070927204328/http://www.vertpaleo.org/publications/jvp/15-707-712.cfm |archive-date=27 September 2007 |url-access=subscription }}</ref><ref name=brinkmanetal1998>{{cite journal |last1=Brinkman |first1=Daniel L. |last2=Cifelli |first2=Richard L. |last3=Czaplewski |first3=Nicholas J. |year=1998 |title=First occurrence of ''Deinonychus antirrhopus'' (Dinosauria: Theropoda) in the Antlers Formation (Lower Cretaceous: Aptian-Albian) of Oklahoma |journal=Oklahoma Geological Survey Bulletin |volume=146 |pages=1–27 |url=http://www.ogs.ou.edu/pubsscanned/BULLETINS/Bulletin146.pdf |archive-date=19 August 2018 |access-date=21 August 2010 |archive-url=https://web.archive.org/web/20180819045405/http://www.ogs.ou.edu/pubsscanned/BULLETINS/Bulletin146.pdf |url-status=live }}</ref> However, the only solid evidence for social behavior of any kind among dromaeosaurids comes from a Chinese trackway which shows six individuals of a large species moving as a group.<ref name="Lietal2007">{{cite journal |first1=Rihui |last1=Li |last2=Lockley |first2=M.G. |last3=Makovicky |first3=P.J. |last4=Matsukawa |first4=M. |last5=Norell |first5=M.A. |last6=Harris |first6=J.D. |last7=Liu |first7=M. |title=Behavioral and faunal implications of Early Cretaceous deinonychosaur trackways from China |year=2007 |pmid=17952398 |journal=Die Naturwissenschaften |volume=95 |issue=3 |pages=185–191 |doi=10.1007/s00114-007-0310-7 |bibcode=2008NW.....95..185L|s2cid=16380823 }}</ref> Although many isolated fossils of ''Velociraptor'' have been found in Mongolia, none were closely associated with other individuals.<ref name=norellmakovicky2004/> Therefore, while ''Velociraptor'' is commonly depicted as a [[pack hunter]], as in ''Jurassic Park'', there is only limited fossil evidence to support this theory for dromaeosaurids in general and none specific to ''Velociraptor'' itself. Dromeosaur footprints in China suggest that a few other raptor genera may have hunted in packs, but there have been no conclusive examples of pack behavior found.<ref>{{cite news | title=Dinosaurs behaving badly: Did velociraptors hunt in packs? | url=https://www.theguardian.com/science/blog/2011/mar/29/dinosaurs-behaviour-raptors-pack-hunters | newspaper=The Guardian | first=Brian | last=Switek | date=29 March 2011 | access-date=17 September 2020 | archive-date=25 May 2023 | archive-url=https://web.archive.org/web/20230525041612/https://www.theguardian.com/science/blog/2011/mar/29/dinosaurs-behaviour-raptors-pack-hunters | url-status=live }}</ref><ref>Long, John, and Schouten, Peter. (2008). ''Feathered Dinosaurs: The Origin of Birds''. Oxford and New York: Oxford University Press. {{ISBN|978-0-19-537266-3}}, p. 21.</ref>
[[File:Velociraptor restraining an oviraptorosaur by durbed.jpg|left|thumb|''V. mongoliensis'' restraining an [[oviraptorosaur]] with its sickle claws]]
In 2011, Denver Fowler and colleagues suggested a new method by which dromaeosaurs like ''Velociraptor'' and similar dromaeosaurs may have captured and restrained prey. This model, known as the "raptor prey restraint" (RPR) model of predation, proposes that dromaeosaurs killed their prey in a manner very similar to extant [[Accipitridae|accipitrid]] [[birds of prey]]: by leaping onto their quarry, pinning it under their body weight, and gripping it tightly with the large, sickle-shaped claws. These researchers proposed that, like accipitrids, the dromaeosaur would then begin to feed on the animal while it was still alive, and prey death would eventually result from blood loss and organ failure. This proposal is based primarily on comparisons between the morphology and proportions of the feet and legs of dromaeosaurs to several groups of extant birds of prey with known predatory behaviors. Fowler found that the feet and legs of dromaeosaurs most closely resemble those of [[eagle]]s and [[hawk]]s, especially in terms of having an enlarged second claw and a similar range of grasping motion. The short [[Tarsometatarsus|metatarsus]] and foot strength, however, would have been more similar to that of [[owl]]s. The RPR method of predation would be consistent with other aspects of ''Velociraptor''{{'}}s anatomy, such as their unusual jaw and arm morphology. The arms, which could exert a lot of force but were likely covered in long feathers, may have been used as flapping stabilizers for balance while atop a struggling prey animal, along with the stiff counterbalancing tail. The jaws, thought by Fowler and colleagues to be comparatively weak, would have been useful for row saw motion bites like the modern day [[Komodo dragon]], which also has a weak bite, to finish off its prey if the kicks were not powerful enough. These predatory adaptations working together may also have implications for the [[Origin of avian flight|origin of flapping]] in [[paravian]]s.<ref name=fowler2011>{{cite journal |last1=Fowler |first1=D.W. |last2=Freedman |first2=E.A. |last3=Scannella |first3=J.B. |last4=Kambic |first4=R.E. |year=2011 |title=The Predatory Ecology of ''Deinonychus'' and the Origin of Flapping in Birds |journal=PLOS ONE |volume=6 |issue=12|page=e28964 |doi=10.1371/journal.pone.0028964 |pmid=22194962 |bibcode=2011PLoSO...628964F |pmc=3237572|doi-access=free }}</ref>

===Scavenging behavior===
In 2010, Hone and colleagues published a paper on their 2008 discovery of shed teeth of what they believed to be a ''Velociraptor'' near a tooth-marked jaw bone of what they believed to be a ''Protoceratops'' in the Bayan Mandahu Formation. The authors concluded that the find represented "late-stage carcass consumption by ''Velociraptor''" as the predator would have eaten other parts of a freshly killed ''Protoceratops'' before biting in the jaw area. The evidence was seen as supporting the inference from the "Fighting Dinosaurs" fossil that ''Protoceratops'' was part of the diet of ''Velociraptor''.<ref name="Hone2010">{{Cite journal |last1=Hone |first1=David |last2=Choiniere |first2=Jonah |last3=Sullivan |first3=Corwin |last4=Xu |first4=Xing |last5=Pittman |first5=Michael |last6=Tan |first6=Qingwei |year=2010 |title=New evidence for a trophic relationship between the dinosaurs ''Velociraptor'' and ''Protoceratops'' |journal=Palaeogeography, Palaeoclimatology, Palaeoecology |volume=291 |issue=3–4 |pages=488–492 |bibcode=2010PPP...291..488H |doi=10.1016/j.palaeo.2010.03.028}}</ref>

In 2012, Hone and colleagues published a paper that described a ''Velociraptor'' specimen with a long bone of an [[azhdarchid]] [[pterosaur]] in its gut. This was interpreted as showing scavenging behaviour.<ref name=hone2012>{{Cite journal | last1 = Hone | first1 = D. | last2 = Tsuihiji | first2 = T. | last3 = Watabe | first3 = M. | last4 = Tsogtbaatr | first4 = K. | title = Pterosaurs as a food source for small dromaeosaurs | doi = 10.1016/j.palaeo.2012.02.021 | journal = Palaeogeography, Palaeoclimatology, Palaeoecology | volume = 331–332 | page = 27 | year = 2012 | bibcode = 2012PPP...331...27H }}</ref>

In a 2024 study by Tse, Miller, and Pittman et al., focusing on the skull morphology and bite forces of various dromaeosaurids, it was discovered that ''Velociraptor'' had high bite force resistance compared to other dromaeosaurids such as ''Dromaeosaurus'' itself and ''Deinonychus'', the latter of which was much larger. It is theorized by the authors that high bite force resistance was an adaptation towards obtaining food through scavenging more often than through active predation in ''Velociraptor''.<ref>{{cite journal | doi=10.1186/s12862-024-02222-5 | doi-access=free | title=Morphological disparity and structural performance of the dromaeosaurid skull informs ecology and evolutionary history | date=2024 | last1=Tse | first1=Yuen Ting | last2=Miller | first2=Case Vincent | last3=Pittman | first3=Michael | journal=BMC Ecology and Evolution | volume=24 | issue=1 | page=39 | pmid=38622512 | pmc=11020771 | bibcode=2024BMCEE..24...39T }}</ref>

===Metabolism===
[[File:Velociraptor MPC-D 100 54 skull CT scan.jpg|thumb|3D scan and nasal cavity reconstruction of ''V. mongoliensis'' skull MPC-D 100/54]]
''Velociraptor'' was [[warm-blooded]] to some degree, as it required a significant amount of energy to hunt. Modern animals that possess feathery or furry coats, like ''Velociraptor'' did, tend to be warm-blooded, since these coverings function as insulation. However, bone growth rates in dromaeosaurids and some early birds suggest a more moderate [[metabolism]], compared with most modern warm-blooded mammals and birds. The [[Kiwi (bird)|kiwi]] is similar to dromaeosaurids in anatomy, feather type, bone structure and even the narrow anatomy of the nasal passages (usually a key indicator of metabolism). The kiwi is a highly active, if specialized, flightless bird, with a stable body temperature and a fairly low resting metabolic rate, making it a good model for the metabolism of primitive birds and dromaeosaurids.<ref name=paul2002 />

In 2023, Seishiro Tada and team examined the nasal cavities of [[ectotherm]] (cold-blooded) or [[endotherm]] (warm-blooded) species, in order to evaluate the [[thermoregulatory]] physiology of non-avian dinosaurs compared to these groups. They found that the size of the nasal cavity relative to the head size of extant endotherms is larger than those of extant ectotherms, and among taxa, ''Velociraptor'' was recovered below the extant endotherms level by reconstructing its nasal respiratory cavity. Tada with team suggested that ''Velociraptor'' and most other non-avian dinosaurs may not have possessed a fully or well-developed nasal thermoregulation apparatus as modern endothermic animals do.<ref>{{Cite journal|last1=Tada |first1=S. |last2=Tsuihiji |first2=T. |last3=Matsumoto |first3=R. |last4=Hanai |first4=T. |last5=Iwami |first5=Y. |last6=Tomita |first6=N. |last7=Sato |first7=H. |last8=Tsogtbaatar |first8=K. |year=2023 |title=Evolutionary process toward avian-like cephalic thermoregulation system in Theropoda elucidated based on nasal structures |journal=[[Royal Society Open Science]] |volume=10 |issue=4 |at=220997 |doi=10.1098/rsos.220997 |pmid=37063996 |pmc=10090882 |bibcode=2023RSOS...1020997T |doi-access=free }}</ref>

===Paleopathology===
{{Main|Theropod paleopathology}}
Norell with colleagues in 1995 reported one ''V. mongoliensis'' skull bearing two parallel rows of small punctures on its frontal bones that, upon closer examination, match the spacing and size of ''Velociraptor'' teeth. They suggested that the wound was likely inflicted by another ''Velociraptor'' during a [[Intraspecific competition|fight within the species]]. Because its bone structure shows no sign of [[Bone healing|healing]] near the bite wounds and the overall specimen was not scavenged, this individual was likely killed by this fatal wound.<ref>{{cite book|last1=Norell|first1=M. A.|last2=Gaffney|first2=E. S.|last3=Dingus|first3=L.|year=1995|title=Discovering Dinosaurs In the American Museum of Natural History|publisher=Knopf Inc.|page=43|isbn=9780520225015 |url=https://archive.org/details/discoveringdinos00nore}}</ref> In 2001 Molnar and team noted that this specimen is MPC-D 100/976 hailing from the Tugrik Shireh locality, which has also yielded the Fighting Dinosaurs specimen.<ref name="molnar-pathology">{{cite book |last1=Molnar |first1=R.E. |editor1-last=Carpenter |editor1-first=Kenneth |editor2-last=Skrepnick |editor2-first=Michael William |editor3-last=Tanke |editor3-first=Darren H |title=Mesozoic Vertebrate Life |date=2001 |publisher=Indiana Univ. Press |isbn=978-0-253-33907-2 |pages=337–363 |url=http://www.worldcat.org/oclc/248649755 |language=English |chapter=Theropod Paleopathology: A Literature Survey|oclc=248649755}}</ref>

In 2012 David Hone and team reported another injured ''Velociraptor'' specimen (MPC-D 100/54, roughly a sub-adult individual) found with the bones of an [[Azhdarchidae|azhdarchid]] pterosaur within its stomach cavity, was carrying or recovering from an injury sustained to one broken rib. From evidence on the pterosaur bones, which were devoid of pitting or deformations from digestion, the ''Velociraptor'' died shortly after, possibly from the earlier injury. Nevertheless, the team noted that this broken ribs shows signs of bone healing.<ref name=hone2012/>